The Read Amplifier board (schematic 10746-1) operates with data signals from the Read Preamplifiers (Transport 1 board) and in conjunction with the Timing & Data board. Read channels A and B operate in the same way;
only channel A is described below.
HEAQ-J
Note: Read/Write heads 3 and 4 not shown.
TRANSPORT BOARD
THRESHOLD AND PEAK DETECTOR
THRESHOLD AND PEAK' DETECTOR
DERIVED DATA A
RERR
I
INSERTED I
CLOCK A I I
D-RDCL
I I IINSERTED
I
CLOCKB
DERIVED DATA B
READ AMPLIFIER BOARD
READ CLOCK A
READ CLOCK B
SHIFT RDXFR
RDXFR SHIFT
SHIFT REGISTER
A
SHIFT REGISTER
B
TIMING & DATA BOARDB
STORAGE A
STORAGE B
OBT OUTPUT
(ODD)
OBT OUTPUT
(EVEN)
TRI-OATA
ONE RECORD-ONE 16-BIT WORD 1100110011001100
5
so "sec
1>.1.</70"sec
u
*These pulses may be absent on channel B.
further by a combination of two amplifiers (ML20). The outputs of ML20 are the Read Amp and Read Amp signals, which are identical except that Read Amp is lS0° out of phase with Read Amp. The ML20-7 output is fed to a limiting circuit consisting of R1S, CR5, Ql, and R19 to produce the Derived Data output at pin 45 (high for a 1 data transition and low for a 0 data transition).
The negative-going portions of the ML20 outputs are fed through CRl and CR2 to a 1.5-v threshold circuit, R9 and RiO. Data signals exceeding 2 v are transferred to the peak detector circuit (ML19). This circuit is essentially a differentiator followed by a limiter, with the output clamped to +3.5 v and -0.7 v. The RC circuit consisting of Cl0, R16, and R17 together with ML15-6 produces a positive pulse when the output of ML19 goes negative, corresponding to a peak of the Read waveform. This pulse is ANDed at MLS-S with the Read Enable signal from ML10-11 to produce the Data Clock signal at pin 43.
Data-derived clock pulses are used to synchronize a sawtooth generator to the timing information from the tape. The first data-derived clock pulse sets ML9-G, a latch which turns on the sawtooth generator (Q2, R20, R21, Cll, ML14). The timing sawtooth generates the Inserted Clock pulses when there are no half-cell transitions on the tape.
Comparator ML14 triggers at about +5 v, and a positive pulse appears at ML10-G to drive a three-stage binary counter (ML5 and ML4-12). The decoded output of the counter is gated with the input pulse to produce the Read Stop pulse at pin 29 when the counter state is G.
This occurs when no more clock pulses are derived from the tape. In effect, the inter-record gap produces the Read Stop signal. The counter is reset to 0 by the data-derived Read Clock.
Error detection is conditional on the counter state being out of synchronization with the data-derived Read Clock.
If the counter is in an even state (pin 31 high) at the time of an Inserted Clock pulse, J-K flip-flop ML4-9 is set to 1; at the end of the data word, the Read Transfer (RDXFR) pulse at pin 39 transfers this error signal through ML3-S to ML10-S to provide the Record Error
Command pulse at pin 23.
The RDCL (Read Data Clock) pulses are generated on the Read Amplifier board by J-K flip-flops ML2-12 and ML3-12. The Read Transfer B (RDXFR B) pulse sets ML2-12 to 1; RDXFR A sets ML3-12 to 1. When both flip-flops are set to 1, ML7-3 goes low and causes the flip-flops to reset, after a short delay, through ML9-S and ML7-G. The RDCL pulse exits at pin 25 for use in the system. The Read operation is affected next by the Timing & Data board.
TIMING & DATA BOARD 10786-0
The Data and Inserted Clocks (pins 7 and 22) are combined on the Timing & Data board (schematic 107SG-0) at OR gates MLG-12 and MLl-3 to produce the Total Clock and Read Clock signals. The Total Clock drives the five-stage binary counter (described under Write Electronics, Timing
& Data board). Shift pulses for shift registers ML3, MLS, and ML13 are generated by gating the Total Clock with even counter states at ML1-S.
The serially derived data (pin 15) from the Read Amplifier board are fed into the shift register at MLS-l (for lG-bit words), at ML13-1 (12-bit words), or ML3-1 (S-bit words). The gating action is controlled by the AND/OR logic of ML21-S and MLll. The data bits are sequentially shifted in the register by the shift pulses which occur at data times.
After the derived bits are completely assembled in the shift register, they are transferred to the quad-latch storage registers ML4 and ML14. The Read Mode. signal (pin 17) is high, enabling Read data to exit through the Tri-Level gates ML5 and ML15 to the DBT lines. At the counter state 31 (the end of a cycle), a Read Clock pulse at ML22-3 generates the Read transfer (RDXFR) pulse, which in tum generates the Transfer-to-Storage pulse at ML1G-G: the data bits transfer into the storage register and are then available in parallel as DBT outputs.
Interface Electronics
Operation of the interface circuitry is presented in the separate INTERFACE section.
SECTION V MAINTENANCE
INTRODUCTION CartriFile tape units were designed and built with care to provide long, trouble-free usage;
they have demonstrated remarkable reliability under varying conditions of service. To keep the CartriFile tape unit operating efficiently, a program of periodic servicing is recommended.
This section is divided into five parts to help service the CartriFile tape unit with a minimum of effort: Daily Maintenance, Yearly Maintenance, 3-Year Maintenance, Magnetic Head Maintenance, and Troubleshooting. As their headings imply, Daily, Yearly, and 3-Year Maintenance contain those procedures which are to be performed at regular intervals. Magnetic head maintenance is handled separately: the head assembly should be trouble-free for at least 2000 hours of operating time; however, procedures for checking and aligning the heads and for checking head wear are included. Troubleshooting information is presented in table form, listing possible fault conditions and what to investigate should a malfunction occur.
Table 5-1 is a check list keyed to the maintenance intervals, including the tools and test equipment required.
The maintenance time intervals are based on an operating time (tape in motion) of about 8 to 16 hours per week. If usage is significantly higher, shorten the time intervals between servicing accordingly. When servicing the tape unit, perform all of the procedures listed for that time interval and follow the sequence in which the procedures are given.
Table 5-1. Maintenance Schedule
INTERVAL RECOMMENDED MAINTENANCE TOOLS AND EQUIPMENT REQUIRED
Daily Clean head and capstan Cotton swab, Freon solvent or alcohol
Yearly Lubricate capstan motor Shell #33 infusion oil
Replace drive belt, indicator lamps, Component Parts Kit 10691 photosense lamp
Check and adjust actuator 0.012-inch and O.005-inch feeler gauges, 3/16-inch open-end wrench, 0.062-inch Allen wrench, oscilloscope, scratch cartridge
. Check and adjust electronics Oscilloscope, scratch cartridge, CartriFile Exerciser or on-line system access
Check head alignment Oscilloscope, Tri-Data Standard Alignment Tape 10720-3, 0.050-inch Allen wrench
3 years Replace capstan motor Soldering iron, 0.050-inch and 9/64-inch Allen wrenches, Motor Replacement Kit 10692 Replace capstan assembly 7/16-inch open-end wrench. Capstan/Flywheel
Assembly 10043-3
Replace cooling fan Soldering iron, screwdriver, Fan Assembly Crri-Data 00097-005)
Perform complete Yearly Maintenance procedures
Check for head wear
5 years Factory reconditioning: replace head assemblies, actuator assemblies, cartridge detent assembly, capstan motor, capstan bearings, capstan, sensing switches, and power relay. Provide complete checkout and alignment.
TRI-DATA
DAI L Y Every day, before using the CartriFile tape unit, the head and capstan should be cleaned to MAINTENANCE remove loose oxide, dust, or other contaminants. Use cptton swabs and Freon solvent (Miller-Stepehnson Chemical Co., MS-180 Freon TF Degreaser) or denatured alcohol. Occasional cleaning of the photosense lens is also recommended.
1. Remove the cartridges. Grasp the front panel, and pull it outward to remove it.
2. Moisten a cotton swab with solvent. Reach through the cartridge slot and clean the visible surfaces of the head.
3. Apply power to the tape unit. While the capstan rotates, hold a cotton swab moistened with solvent against it. Lightly scrub the capstan from top to bottom.
4. Snap the front panel in place.
YEARL Y The "yearly" maintenance procedures given below should be performed when the CartriFile MAINTENANCE tape unit has accumUlated somewhere between 400 and 800 hours of operating time (tape in motion). The procedures should be followed in the order given: this sequence provides an orderly and thoro~gh checkout in a minimum amount of time. Replacement parts for three Yearly Maintenance procedures are included in the Component Parts Kit 10691.
Begin the maintenance procedures by removing the cartridges and front panel. Clean the head and capstan, then perform all of the procedures given below.
After completing the yearly maintenance procedures, refer to MAGNETIC HEAD MAINTENANCE and check the alignment of the head assembly.
Capstan Motor Lubrication
1. Remove the transport retaining screw under the lower right-hand end of the transport and swing the transport out of the cabinet.
2. At the bottom of the motor, directly across from the mounting flange is an oil hole. Directly above this, at the top end of the motor is a second oil hole. Squirt a small quantity of oil into each hole. Wipe off any excess around the outside of the holes.
Drive Belt Replacement
1. Remove the old drive belt, disengaging it first from the groove in the small pUlley.
2. Install a new drive belt (Tri-Data part no. 00007-002).
Place it in the groove around the large pulley, then stretch it gently and engage the groove in the small pulley.
Lamp Replacement
1. Remove power from the tape unit.
2. Remove the Busy Lamp board mounting screws and swing board on harness for rear access.
3. Swing the spring clips aside and replace the four busy lamps (two upper and two lower) with type 328 (Tri-Data part no. 00041-004), and power indicator lamp with type 327 (Tri-Data part no. 00041-009). Install the red boot on the power indicator lamp.
4.
Return the spring clips to their original position.5-2
5. Return the Busy Lamp board to its original position and secure with the mounting screws.
6. Swing the transport out. The Photosense board is on the right rear of the transport. Unsolder the photosense lamp,and replace it with type 2162 (Tri-Data part no. 00041-007).
7. Solder new lamp in place, and trim excess leads.
8. Swing the transport into place and secure with the retaining screw.
Actuator Adjustment
1. Swing the transport out. With the actuator de-energized, check the gap (see Figure 5-1) with shim stock or 0.012-inch feeler gauge. Adjust backstop screw to obtain this setting (3/16 wrench).
/ ~~
0.012 GAP BACKSTOPSCREW
0.062 ALLEN SCREW WITH LOCK NUT
PANHEAD SCREW
TOP VIEW
Figure 5-1. Actuator' Adjustment Points
2. Place a O.005-inch shim in the gap for tape 1.
Electronics Checkout and Adjustment
The location of all circuit boards, connectors, and terminal boards are shown in Figure 5-3. All of the boards within the card file plus the Transport board contain test points, adjustment points, or both. If desired, timing and waveform diagrams for each circuit board may be consulted during the checkout procedures; these diagrams are Figures 5-9 through 5-16, which are arranged in numerical sequence by circuit board number.
All of the electronic checkout procedures assume access to the on-line system. Electronics adjustments may, however, be performed without on-line access through the use
TRANSPORT TOP VIEW
JIO J9 J8 J7 J6 J5 __ J4
Figure 5-3. Location of Electronics Assemblies, Connectors, and Terminals
J3
TRI-OATA
CAUTION
Avoid shorting out IC's and other circuit components. NEVER remove or install a printed circuit board while power is applied to the tape unit.
NOTE
If difficulty is encountered in adjusting the electronics (Le., certain voltages given in the procedures cannot be obtained), the problem may be caused by a faulty component on a circuit board. Isolate the faulty component and replace it using normal circuit board repair procedures.
REGULATOR BOARD 10790-0
Measurements must be made with a d-c VTVM capable J.lsec. Adjust potentiometer R27 to the correct timing.
READ AMPLIFIER BOARD 10746-1
1. Turn the tape unit power off. Place the Read
PHOTOSENSE BOARD 10972-0
1. Set the oscilloscope time base to 1 msecjcm, and
5. Set the weak channel's potentiometer to mid-position.
Adjust R12 such that this channel switches from 4 v at Load Point to less than 1 v off Load Point. After obtaining the proper R12 setting, do not adjust it further.
6. Adjust the remaining three channels, using each channel's potentiometer only. The associated test point voltage for each channel should be greater than 3.5 v on-tab and less than 1 v off-tab.
7. After adjusting all channels, check that the voltage at TP5 on the Actuator Driver board is not higher than about 12 v.
8. If the TP5 voltage exceeds 12 v, check the regulator circuit, photo-transistors, and photosense lamp for a faulty components.
3-YEAR When the CartriFile tape unit has accumulated 1200 to 2400 hours of operating time (the MAINTENANCE approximate average range of usage in three years), the capstan motor, capstan, and cooling fan should be replaced. Procedures for the replacement of these items are given below. Parts required are the Motor Replacement Kit 10692, Capstan/Flywheel Assembly 10043-3, and a Fan Assembly (Tri-Data part no. 00097-002).
Perform the replacement procedures below first, then perform the YEARLY MAINTENANCE procedures in their entirety.
After completing the yearly procedures, refer to MAGNETIC HEAD MAINTENANCE and check the head assembly for wear.
Capstan Motor Replacement
1. Remove the cartridges, front panel, and a-c power cord.
2. Remove the transport retaining screw, and swing the transport out of the cabinet.
3. Remove the drive belt, disengaging it first from the groove in the motor pulley.
4. Using a 0.050-inch hex key, loosen the two set screws in the motor pulley. Remove the pulley.
5. Trace the two leads from the motor and locate the point at which they connect to a plastic connector.
Disconnect the connector.
6. Using a 9/64-inch hex key, remove the four socket-head cap screws with lockwashers which pass through the transport side and secure the motor.
7. Remove and discard the motor.
8. Mount the new drive motor using the hardware removed in step 6. Connect the plastic connectors.
9. Install the pulley removed in step 4 on the motor shaft. Note that this pulley has two grooves: the larger diameter is for 50-Hz operation, the smaller for 60-Hz operation. The pulley must be placed on the shaft so that the desired groove is closest to the motor. Align the appropriate pulley groove with the groove in the capstan flywheel. Tighten the setscrews securely.
Capstan Assembly Replacement
This procedure assumes that the capstan motor has just been replaced and continues with the drive belt not yet installed.
1. Grasp the flywheel and hold it firmly. Using a 7/16-inch end wrench, loosen the self-locking nut on the top of the capstan shaft.
2. Remove the nut and the washer beneath it. Withdraw the capstan/flywheel from the bottom of the transport.
3. Place the old spacer on the shaft of a new 10043-3 capstan/ijywheel. Slide the spacer all the way down the shaft un til it seats against the flywheel.
4. Insert the capstan/flywheel shaft into the bearing at the bottom of the transport. Slide it upwards, guiding it through. the upper bearing. Care should be taken that no damage occurs to the plastic-coated surface of the shaft.
5. Place the old washer on the top of the shaft.
6. Install the self-locking nut on the top of the shaft.
7. Insert a 0.002-inch shim between the upper bearing and the washer. Grasp the flywheel below the transport and tighten the self-locking nut at the top until the shim is just held snugly. Remove the shim and tighten the nut one-eighth additional turn.
8. Install a new drive belt (Tri-Data part no. 00007-003).
Place it in the groove around the flywheel, then stretch it gently and engage the groove in the small pulley.
9. Swing transport into place and fasten.
Cooling Fan Replacement
The following steps assume that the tape unit is in normal operating position and viewed from the rear.
NOTE
Certain systems include interface cables and components which project outward from the rear panel, preventing it from pivoting on its hinge. The interfering components must be removed before proceeding with the steps below. Refer to the separate INTERFACE section of this manual for interface installation instructions.
1. Unplug the power cord from the rear panel.
2. Remove the two No.6 panhead screws, lockwashers, and flat washers at the left-hand edge of the rear panel. The rear panel may now be pivoted out.
3. Locate the black plastic protective cover with the CAUTION note. Withdraw the two No. 4 panhead screws, lockwashers, and flat washers. Remove the cover.
4. Two terminal strips are now exposed, as shown in Figure 5-4. The terminal strip on the left is TS2, the other is TS1. Terminals are numbered 1 through 4 consecutively, with terminal 1 nearest the rear panel.
5. Carefully holding wires away from the area, unsolder each of the leads connecting the fan to the terminal strips.
6. Using a screwdriver, remove the four screws which secure the fan and guard. Discard the fan.
7. Install a new cooling fan (Tri-Data part no.
00097-005).
8. Dress the leads of the new fan to the terminal strips: brown to TS2-1, blue to TS2-2, and yellow to TS1-4.
9. Solder the leads to the terminal strips.
10. Install the black plastic cover using the hardware removed in step 3.
Figure 5-4. Power Supply Terminals
11. Swing the rear panel in and secure in place with the hardware removed in step 2.
12. Install any interface components removed. Connect the power cord.
MAGNETIC HEAD The CartriFile 40 tape unit contains four read/write magnetic heads mounted as an assembly, MAl NTENANCE with the heads capable of separate vertical and azimuth adjustment. The alignment of the heads can be checked once a year following the electronics checkout and adjustment procedures. The heads should also be checked for wear at about three years, in case replacement is required at that time.
Head AI ignment
Correct head alignment is crucial to the reliable interchange of cartridges between tape units. Vertical alignment ensures that the active track on. the head will be properly registered with the track location on the tape. Azimuth alignment produces minimum skew between the data tracks.
Normally, there should be no need for realignment during the life of the head assembly. The adjustments are sealed at the factory, and further adjustments should not be attempted unless there is a definite indication of misalignment.
A dual-trace oscilloscope is required to check for proper alignment of the head. However, if a misalignment is indicated by the check, it will be necessary to use the
5-6
Tri-Data Standard Alignment Tape (part no. 10720-3) to isolate the misalignment to one tape unit (where several are in lise) and to realign the head.
1. Connect the A and B oscilloscope channels to TP6 and TP5 of the Read Amplifier board. Sync the oscilloscope from TP5 of the Motion Control 1 board.
Set the gain to 5 v/division (0.5 v/division for a 10:1 probe), horizontal sweep time to 5 msec/division, and EXT sync. The start period and data block will be displayed.
2. Observe channel A while reading a tape written in blocks of the bit pattern 101100110011. Raise the gain to 1 v/division and center the trace so that the start period is centered vertically. Vertical misalignment will be indicated by a signal in excess of 0.5 v pk-pk during
the start period preceding the data block. This signal
the start period preceding the data block. This signal